Cup 2 - Track running pressures
Discussion
Do any of you Gentlemen have motorsport experience of the running Cup 2's? If so where are you running optimum hot pressures? We ran the original cups at 2.1 bar front and rear on all GT3 set ups but I read that the cup 2's should be run at higher pressures. I took my 964 to Snetterton recently to shake it down. With pressures set at 2.2, although the cups were quite grippy there was a lot of tyre squeal. Something that Have never experienced before on the earlier cups. The temperature spread across the tyres showed that I wasn't running quite enough camber - esp on the rears - but it was not fat out so the footprint was good and the car had a good balance. Still a lot more camber than a standard 964RS. No balance issues to drive around.
Here is a short in car clip. if you turn up the sound you can hear the squeal.
https://www.youtube.com/watch?v=qXzMkKmdUZY
Is this normal? If its camber thats causing it, most cars would sound a whole lot worse. Suspect temps are wrong
Here is a short in car clip. if you turn up the sound you can hear the squeal.
https://www.youtube.com/watch?v=qXzMkKmdUZY
Is this normal? If its camber thats causing it, most cars would sound a whole lot worse. Suspect temps are wrong
I just work on the rule if my centre is hotter than the 2 sides then I take a bit out.
Most cars are camber ltd on track and also roll too much.
On my Spyder I do 4 laps, let some out, let it cool for 30 mins, do 4 laps, let some out and they seem stable after that.
No point letting it out cold, it will scub your tyres, and no point staying out when you 1st go out for lap after lap.
ends up for me about 30/31 psi front to rear.
That may be 3 psi out on the 1st run and another 2 psi out on the 2nd run, then fine tune a psi or so if I feel like it.
Most cars are camber ltd on track and also roll too much.
On my Spyder I do 4 laps, let some out, let it cool for 30 mins, do 4 laps, let some out and they seem stable after that.
No point letting it out cold, it will scub your tyres, and no point staying out when you 1st go out for lap after lap.
ends up for me about 30/31 psi front to rear.
That may be 3 psi out on the 1st run and another 2 psi out on the 2nd run, then fine tune a psi or so if I feel like it.
Edited by PorscheGT4 on Wednesday 19th August 12:01
I've only managed around 20 mins at race pace on Cup 2s so far but I was running 2.1 front 2.2 rear (hot) on a GT3 with approx 3 deg camber front and rear, with a touch of toe in. I won't get a chance to experiment with this before the next outing, but balance and grip felt as good as I can remember. No squeal that I recall or maybe I just wasn't pushing hard enough...
I was really impressed with Cup 2s, more so than the original Cups because the originals telegraphed less info just before breakaway.
I was really impressed with Cup 2s, more so than the original Cups because the originals telegraphed less info just before breakaway.
30 psi hot all round is the favourite setting of many 964RS owners who use the original cups and Toyo R888s. I use the same on my C2 (R888s). I think Mel Spear uses the same for his slick shod 964 cup. I don't know of anyone using the Cup2 on a 964 but would guess similar pressures would work? However, I should add that the pressures mentioned are all for 17 inch tyres.
Although you asked about Motorsport perspective, I thought I'd mention track day experience if of benefit to others. Perhaps we can identify which up front. So...
Track day
996 GT3. Cup 2s with car running double stiff springs.
Hot: 30 psi front / 33 psi rear
I find during warm up phase if tyre rubber is not fully up to temp then the tyres can get a bit squeaky and slippy after 3 fast laps. However once fully settled (late morning and afternoon sessions) they are very stable.
Track day
996 GT3. Cup 2s with car running double stiff springs.
Hot: 30 psi front / 33 psi rear
I find during warm up phase if tyre rubber is not fully up to temp then the tyres can get a bit squeaky and slippy after 3 fast laps. However once fully settled (late morning and afternoon sessions) they are very stable.
On PSS's I start off at 34 road, and take out 8 psi, for the warm up laps.
Generally speaking after the warming up laps I'm at around 30 psi and then I go out for a good 20 min session and fine tune to 30 all round hot, after a good cooling down lap --- which generally involves taking out around another 4 psi.
Wet, I would start by taking out 4 psi ...
At the end of the dry track day, whatever the pressure, I put 10psi back in and drive home. Then fine tune the following day once properly cold. Wet, it depends upon the day ...
Generally speaking after the warming up laps I'm at around 30 psi and then I go out for a good 20 min session and fine tune to 30 all round hot, after a good cooling down lap --- which generally involves taking out around another 4 psi.
Wet, I would start by taking out 4 psi ...
At the end of the dry track day, whatever the pressure, I put 10psi back in and drive home. Then fine tune the following day once properly cold. Wet, it depends upon the day ...
This info from Michelin was posted recently by another member, and is a good starting point if you haven't already seen:
MICHELIN Pilot Sport CUP 2 is a track tire (semi slick tire), which meets the legal requirements for use on the public highway. This tire has been specifically optimized for use on a dry track. On a wet track or road, where there is a risk of aquaplaning, adapt your driving style by reducing your speed and leaving the safety and driver assistance systems connected
For track and road handling reasons, the fitting of a set of 4 MICHELIN Pilot Sport Cup 2 is strongly advised
Before Fast Circuit Use always
o Verify the condition of your tyres, checking for wear & damage
o Build up to the temperature of the tyres gradually by a few more moderate paced laps
After running on the circuit and before returning to the road, consider
• Always check the condition of your tyres to ensure they are safe and comply with relevant local traffic laws
• Allow the tyres to cool ideally before making appropriate pressure adjustments
• Re-adjust your cold tyre pressures in accordance with the pressure recommended by the car manufacture
• If they have been disconnected/switch off, re-instate all safety systems, driver aids and tyre pressure monitoring
INFLATION PRESSURE ADVICES
On the track for majority of car (*)
Cold tires
• Inflate the MICHELIN Pilot Sport Cup2 with a pressure between 1.7 bar (24 psi) and 1.8 bar (26 psi) front & rear
• Never allow the pressure to be below 1.5 bar (22 psi)
Hot tires
• The optimal operating pressure of the MICHELIN Pilot Sport Cup2 must be between 2.3 bar (33 psi) and 2.5 bar (36 psi) Front & Rear
• Never allow the tyres to run below 2,0 bar (29 psi) HOT
Road use
• Use the cold pressures recommended by the car manufacturer
This information applies to the majority of cars regulalry used on circuits e.g: Audi R8, BMW M3 E90 / E46 / F80, Porsche GT3 / GT3 RS / 911 Carrera / Boxster/Cayman, Renault Megane RS, Subaru Impreza/WRX/BRZ
For all other cars and in particular for heavy cars or for any other specific information, please contact your local website www.michelin...
CAUTION !
• If not used for a prolonged period of time, remove the MICHELIN Pilot Sport Cup 2 tyres (mounted on their wheels) and reduce their pressure to half their normal value to store
• Store tyres in a clean, dry area, away from direct sunlight and above 0°C (32°F) in accordance with the information provided by Michelin in technical documentation or their website
• Do Not use, store or handle MICHELIN Pilot Sport Cup 2 tyres at ambient temperatures below -10°C (14°F)
• Under these conditions the tyre components can degrade, resulting in reduced performance, and at low temperatures can lead to cracks in the tyre compound and hence reduce potential in use
• Never use a tyre with cracks, breaks or damage to the sidewall or tread. If in any doubt please consult your local Michelin technical department
• When using for long periods in an intensive manner on circuits, please be aware that damage can occur to the tyre and its carcass from regularly running over the kerbs at the side of the circuit
• In the case of prolonged running over the kerbs (or also running heavily off the track) it is advisable to verify the internal condition of the tyre and it’s construction by demounting it from the wheel and having it professionally inspected for any damage, both on the interior and the exterior of the tyre
• It is advisable to visually check the tyres after each run, prior to going back onto the circuit
MICHELIN Pilot Sport CUP 2 is a track tire (semi slick tire), which meets the legal requirements for use on the public highway. This tire has been specifically optimized for use on a dry track. On a wet track or road, where there is a risk of aquaplaning, adapt your driving style by reducing your speed and leaving the safety and driver assistance systems connected
For track and road handling reasons, the fitting of a set of 4 MICHELIN Pilot Sport Cup 2 is strongly advised
Before Fast Circuit Use always
o Verify the condition of your tyres, checking for wear & damage
o Build up to the temperature of the tyres gradually by a few more moderate paced laps
After running on the circuit and before returning to the road, consider
• Always check the condition of your tyres to ensure they are safe and comply with relevant local traffic laws
• Allow the tyres to cool ideally before making appropriate pressure adjustments
• Re-adjust your cold tyre pressures in accordance with the pressure recommended by the car manufacture
• If they have been disconnected/switch off, re-instate all safety systems, driver aids and tyre pressure monitoring
INFLATION PRESSURE ADVICES
On the track for majority of car (*)
Cold tires
• Inflate the MICHELIN Pilot Sport Cup2 with a pressure between 1.7 bar (24 psi) and 1.8 bar (26 psi) front & rear
• Never allow the pressure to be below 1.5 bar (22 psi)
Hot tires
• The optimal operating pressure of the MICHELIN Pilot Sport Cup2 must be between 2.3 bar (33 psi) and 2.5 bar (36 psi) Front & Rear
• Never allow the tyres to run below 2,0 bar (29 psi) HOT
Road use
• Use the cold pressures recommended by the car manufacturer
This information applies to the majority of cars regulalry used on circuits e.g: Audi R8, BMW M3 E90 / E46 / F80, Porsche GT3 / GT3 RS / 911 Carrera / Boxster/Cayman, Renault Megane RS, Subaru Impreza/WRX/BRZ
For all other cars and in particular for heavy cars or for any other specific information, please contact your local website www.michelin...
CAUTION !
• If not used for a prolonged period of time, remove the MICHELIN Pilot Sport Cup 2 tyres (mounted on their wheels) and reduce their pressure to half their normal value to store
• Store tyres in a clean, dry area, away from direct sunlight and above 0°C (32°F) in accordance with the information provided by Michelin in technical documentation or their website
• Do Not use, store or handle MICHELIN Pilot Sport Cup 2 tyres at ambient temperatures below -10°C (14°F)
• Under these conditions the tyre components can degrade, resulting in reduced performance, and at low temperatures can lead to cracks in the tyre compound and hence reduce potential in use
• Never use a tyre with cracks, breaks or damage to the sidewall or tread. If in any doubt please consult your local Michelin technical department
• When using for long periods in an intensive manner on circuits, please be aware that damage can occur to the tyre and its carcass from regularly running over the kerbs at the side of the circuit
• In the case of prolonged running over the kerbs (or also running heavily off the track) it is advisable to verify the internal condition of the tyre and it’s construction by demounting it from the wheel and having it professionally inspected for any damage, both on the interior and the exterior of the tyre
• It is advisable to visually check the tyres after each run, prior to going back onto the circuit
Thank you for your replies. I don't think that 2.2 is far off optimum. I do ask a lot of a tyre but have never experienced anything other than slick like behaviour from cups before. They just hang in without any squeal at all.
Out of the box the car was quick enough to be on the third row of the grid the last future classic race at Snett so the pace potential is there from the chassis and tyre combo. Let's see what difference more neg camber (3 deg front and 2.5 rear ) will have on the tyre. I think with a sharper set up and a remap there's another 1.5-2 seconds more to come. That would put in on the first or second row. Not bad for a runty little 25 year old 911 with Aircon and electric windows!
Will report back.
Out of the box the car was quick enough to be on the third row of the grid the last future classic race at Snett so the pace potential is there from the chassis and tyre combo. Let's see what difference more neg camber (3 deg front and 2.5 rear ) will have on the tyre. I think with a sharper set up and a remap there's another 1.5-2 seconds more to come. That would put in on the first or second row. Not bad for a runty little 25 year old 911 with Aircon and electric windows!
Will report back.
I found at spa I could run pretty much flat out for the 40 min races starting at 21/22 they went up to 27. Can't seem to run them near 30 like I used to on cup 1s. Rich chamberlain struggled in race 1 he tried this and went past me near the start of race 2 so shouldn't of told him haha! We were keeping the newer m3s and tuscans at bay who insist on using 888s. Try them lower for what it's worth, I couldn't believe the difference
Gassing Station | Porsche General | Top of Page | What's New | My Stuff